Health officials halted the most recent vaccination drive late last week because an “uncertain and threatening situation for the frontline polio workers has emerged and we need to save the programme from a further major damage” an order said. Post campaign monitoring was also stopped.

Polio officials are now deciding how to adapt the campaign, which currently takes place in nationwide drives every six weeks. The high frequency aims to ensure no children are missed, but officials say it also frustrates parents who are being asked to give their children drops up to 10 times a year. More infrequent vaccination drives, perhaps once a quarter could be one proposal. A new nationwide information campaign is also likely to be launched to fight misconceptions about the vaccinations.

Poliomyelitis is on the cusp of eradication, with the wild virus only found in Pakistan, Afghanistan and Nigeria. Last year there were 33 cases, down from 350,000 annual cases when the global eradication drive began in 1988.